This observation by William James holds no less truth today than when he made it over a century ago. The reason that so many people never fulfill their potential is not a lack of intelligence, opportunity or resources, but a lack of belief in themselves. Or put another way, too little self-confidence. Without it, you can do little, with it, you can do anything!

But what is confidence, anyway?

Often people think of confidence as something that the lucky few are born with and the rest are left wishing for. Not true. Confidence is not a fixed attribute; it’s the outcome of the thoughts we think and the actions we take. No more; no less. It is not based on your actual ability to succeed at a task but your belief in your ability to succeed. For instance:

Your belief in your ability to change job or career, exit a relationship, or start a business.

It’s been long established that the beliefs we hold – true or otherwise - direct our actions and shape our lives. The good news is that new research into neural plasticity reveals that we can literally rewire our brains in ways that affect our thoughts and behavior at any age. Which means that no matter how timid or doubt-laden you’ve been up to now, building self-confidence is largely what psychologists called volitional. Or to use layman language: “By choice.” With consistent effort, and the courage to take a risk, we can gradually expand our confidence , and with it, our capacity to build more of it!

Of course, confidence can wax and wane throughout our lives. It’s boosted when we experience a win or receive praise. It takes a hit when our efforts fall short of the mark, we're criticized, rejected or simply feel a lack of external recognition. We’re only human after all. It’s therefore vital not to become overly reliant on external affirmation to prop up our self-worth, but to take ownership for taking the worthwhile actions needed to sustain it. Which begs the question:

How do you build the confidence needed to overcome your challenges and achieve your goals, particularly when you don’t first succeed?

Below are five strategies, all backed by hard science, to help you on your way, beginning with the most powerful of them all.

Act As If...

Just as the simplest recipes turn out the best dishes, so too the simplest advice can produce the strongest results. The single most powerful way to build confidence is to act with the confidence you aspire to have. That is, to act as if you already possess the confidence you aspire to have. Speak up. Reach out. Stretch yourself. Exit your comfort zone! While there are reams of research on building a robust sense of self-confidence -- and banishing the self-doubt that can undermine it - it basically boils down the decision you take to back yourself and take a risk.

Alex Malley, bestselling author of The Naked CEO shared with me, “The only way to build self-confidence is to take a risk and take action despite your fear of failure, messing up or embarrassment. If things work out, then you now know you can do more than you think. If things don’t work out, you now know that you can handle more than you think. Either way, you’re better off.”

As CEO of CPA Australia, a leading global accounting body over 150,000 members globally, Malley has seen far too many people stay in the same role for too long because they have bought into the confidence-shrinking (and career-limiting!) belief that they can’t do anything else.

I’ve seen the same myself. Someone achieves a modicum of career success only to become unwilling to do anything that might put it at risk. So they start spending more time in their comfort zone where there is minimal risk of failure and little threatens their confidence. At least in the short term! But when we stop reaching we stop learning and when we stop learning, we stop growing...

Growing our knowledge and skills.

Growing our value.

Growing our competence.

Growing resilience.

Growing our influence.

Growing self-efficacy.

Growing confidence in our ability to make things happen!

Rather than playing to win and forging new ground, people become driven by a fear of losing the ground they already have (which I’ve written about previously.) Their unwillingness to lay their reputation and security on the line in the short term results in missing out bigger opportunities down the road; opportunities that go to those who’ve never stopped stretching, growing, learning and strengthening their confidence along the way.

“Think of something you have always wanted to do but have avoided because you fear it could be embarrassing,” advises Malley. “Now clear your mind and give it a go.” It's not only vital to your future success, but failing to take a risk and "have a go" can ultimately put the confidence you have now at risk. That is... If you don't use it, you lose it!

Think of someone you greatly admire who radiates a quiet sense of confidence, and think about what they would do or say if they were facing your current challenges and opportunities. Channel their self-confidence, certitude and bravery. As I shared in Find Your Courage, I once coached a female client who had been struggling to speak up at her weekly (male dominated) management meetings to imagine she had the confidence of Hilary Clinton. To her surprise, she found herself injecting her opinion into the conversation as never before and feeling all the more powerful for it. Ten years on she is now running the company. (Below is an interview I did about the confidence gap between men and women.)

Visualization is a highly effective tool for building confidence. It can activate the same neural circuitry in the brain as doing something in reality. So to help you ACT AS IF, try imagining yourself doing (or saying) whatever it is you want to do with a quiet but unshakeable believe in your ability to do it well. If it's a conversation you need to have, practice having it a few times before hand. It will make a difference.

Like all emotions, confidence breeds confidence. So whether you’re in the C-suite or a sales rep, make the conscious and courageous decision not to give self-doubt the power to keep you from pursuing a bold ambition, have a tough conversation, or lay your pride on the line for a cause bigger than your ego. As Katty Kay and Claire Shipman wrote in The Confidence Code, “Confidence is hard to define but easy to recognize. With it, you can take on the world; without it, you live stuck at the starting block of your potential.”

Bestselling author, speaker & leadership authority, Margie Warrell emboldens leaders to expand their vision and become braver change-makers. An advisory board member of Forbes School of Business & Technology, Margie draws on her diverse international background to ...